This invention relates to a safety device, and in particular to a safety device responsive to the relative rotational position of two rotatable members.
Especially in vehicles such as snowmobiles, the risk exists that a throttle valve may become stuck open, so that when the throttle lever is released, the throttle valve does not close. This is potentially dangerous, because the vehicle would then not stop. One place where such a situation can occur is in a snowmobile engine, wherein water might get into the throttle linkage and freeze, whereby to hold the throttle valve open, even though the throttle lever is released.
It is an object of this invention to provide a safety device which will stop the engine if the throttle valve itself remains open but the throttle lever returns to a position where the throttle should have closed. The throttle valve and throttle lever are then said to be "out of synchronism". Immobilization of the throttle valve as a consequence of ice in the linkage, is only one example of disabling situations which tend to hold a linkage in an out-of-synchronism position. Mechanical damage to the linkage could also cause such a condition.